Looks like I can reproduce this… will look at it today.
ok… GoControl uses OnLayerChanged calls to catch when newlayer = null, and it calls DisposeControl to clean up the control.
However, when in undo/redo, the set layer code doesn’t make calls to OnLayerChanged (to avoid shoot-yourself-in-the-foot side-effects in undo/redo).
So, we’ve looked at this carefully and decided the way to fix this is to make an exception when in undo/redo for GoControl and go ahead and call OnLayerChanged.
The good news is that will fix the problem, and we can make that change in the upcoming 4.1. The bad news is I don’t see any neat and tidy way to work around this in an earlier version. (you might be able to watch for DocumentChanged events and call GoControl.DisposeControl when you see a WebBrowser being deleted… haven’t tried that.)
Thanks for the fix, do you have a release time frame for v4.1?
Around April 12th, which is the release date of Visual Studio 2010.